What was the official position of "Secretary of Nanjing Military Office" in Ming Dynasty, and what was it specifically responsible for?

Small officials are used by the people. The Ming dynasty was divided into twelve prisons, four divisions and eight bureaus, which was the so-called twenty-four yamen. Each prison has a eunuch, four officials, a left supervisor and a right supervisor, a left supervisor and a right supervisor, five officials, a Canon, and six officials. The rest are out of stock, including management, writing, responsible for the company, writing and supervision. The work of a secretary is very vague. According to different units, some take care of toilet paper, some take care of bathing, needlework and even oil, salt, sauce and vinegar. Equivalent to the current small director.